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1.
Fertilizer N use in Japan has decreased by about 30% from 1960 to 2000, while keeping a little increase in cereal yields. This has resulted in a significant increase in apparent nitrogen use efficiency, in particular for rice. On the other hand, national N Icad on the environment associated with the production and consumption of domestic and imported agricultural products has almost tripled during this period, mainly due to the dramatic increase of imports of food and feedstuffs. The environmental problems, including water and air pollution, caused by the excessive loads of N are serious public concerns and there is an urgent need to minimize N losses from agricultural production. In order to meet the necessity for reducing the environmental impacts by excess N, political and technological measures have been taken at regional and country levels. In recent years, the Japanese government has embarked on a series of policies to encourage transition to an environmentally conscious agriculture. Promoting proper material circulation with reducing fertilizer impact and utilizing biomass and livestock wastes is emphasized in these policies. The effectiveness of environmental assessment and planning for reducing regional and national N Icad has been discussed. Implementation of environmentally friendly technologies and management, both conventional and innovational, have been developed and adopted in Japanese agriculture. The effectiveness of conventional technologies in reducing environmental reactive N has been re-evaluated. Innovative technologies, such as use of controlled availability fertilizers and livestock wastes compost pellets, are being investigated and extended.A comprehensive approach that applies political and technological measures with closer cooperation is necessary to control reactive N in the environment.  相似文献   

2.
Fertilizer N use in Japan has decreased by about 30% from 1960 to 2000, while keeping a little increase in cereal yields. This has resulted in a significant increase in apparent nitrogen use efficiency, in particular for rice. On the other hand, national N load on the environment associated with the production and consumption of domestic and imported agricultural products has almost tripled during this period, mainly due to the dramatic increase of imports of food and feedstuffs. The environmental problems, including water and air pollution, caused by the excessive loads of N are serious public concerns and there is an urgent need to minimize N losses from agricultural production. In order to meet the necessity for reducing the environmental impacts by excess N, political and technological measures have been taken at regional and country levels. In recent years, the Japanese government has embarked on a series of policies to encourage transition to an environmentally conscious agriculture. Promoting proper material circulation with reducing fertilizer impact and utilizing biomass and livestock wastes is emphasized in these policies. The effectiveness of environmental assessment and planning for reducing regional and national N load has been discussed. Implementation of environmentally friendly technologies and management, both conventional and innovational, have been developed and adopted in Japanese agriculture. The effectiveness of conventional technologies in reducing environmental reactive N has been re-evaluated. Innovative technologies, such as use of controlled availability fertilizers and livestock wastes compost pellets, are being investigated and extended. A comprehensive approach that applies political and technological measures with closer cooperation is necessary to control reactive N in the environment.  相似文献   

3.
Ammonia emissions from the agricultural sector give rise to numerous environmental and societal concerns and represent an economic challenge in crop farming, causing a loss of fertilizer nitrogen. Ammonia emissions from agriculture originate from manure slurry (livestock housing, storage, and fertilization of fields) as well as urea-based mineral fertilizers. Consequently, political attention has been given to ammonia volatilization, and regulations of ammonia emissions have been implemented in several countries. The molecular cause of the emission is the enzyme urease, which catalyzes the hydrolysis of urea to ammonia and carbonic acid. Urease is present in many different organisms, encompassing bacteria, fungi, and plants. In agriculture, microorganisms found in animal fecal matter and soil are responsible for urea hydrolysis. One strategy to reduce ammonia emissions is the application of urease inhibitors as additives to urea-based synthetic fertilizers and manure slurry to block the formation of ammonia. However, treatment of the manure slurry with urease inhibitors is associated with increased livestock production costs and has not yet been commercialized. Thus, development of novel, environmentally friendly and cost-effective technologies for ammonia emission mitigation is important. This mini-review describes the challenges associated with the volatilization of ammonia in agriculture and provides an overview of the molecular processes of urea hydrolysis and ammonia emissions. Different technologies and strategies to reduce ammonia emissions are described with a special focus on the use of urease inhibitors. The mechanisms of action and efficiency of the most important urease inhibitors in relation to agriculture will be briefly discussed.  相似文献   

4.
The nitrogen cycle of pre-industrial ecosystems has long been remarkably closed, in spite of the high mobility of this element in the atmosphere and hydrosphere. Inter-regional and international commercial exchanges of agricultural goods, which considerably increased after the generalization of the use of synthetic nitrogen fertilizers, introduced an additional type of nitrogen mobility, which nowadays rivals the atmospheric and hydrological fluxes in intensity, and causes their enhancement at the local, regional and global scales. Eighty-five per cent of the net anthropogenic input of reactive nitrogen occurs on only 43 per cent of the land area. Modern agriculture based on the use of synthetic fertilizers and the decoupling of crop and animal production is responsible for the largest part of anthropogenic losses of reactive nitrogen to the environment. In terms of levers for better managing the nitrogen cascade, beyond technical improvement of agricultural practices tending to increase nitrogen use efficiency, or environmental engineering management measures to increase nitrogen sinks in the landscape, the need to better localize crop production and livestock breeding, on the one hand, and agriculture and food demand on the other hand, is put forward as a condition to being able to supply food to human populations while preserving environmental resources.  相似文献   

5.
In this article we show that technological development in agriculture exhibits general trends when assessed on a large scale. These trends are generated by changes in the larger socioeconomic context in which the farming system operates. We characterize agricultural performance by land and farm labor productivity and the pattern of use of technological inputs. By means of a cross-sectional analysis of agricultural performance of 20 countries (at the national level), we show that increases in demographic pressure and socioeconomic pressure (increases in average income and labor productivity) in society are the main driving forces of technological development in agriculture. Further, it is shown that the ecological impact of farming (environmental loading) is linked to the particular combination of land productivity and labor productivity at which the agricultural sector operates (through the particular mix and the level of inputs used in agricultural production). Briefly we discuss the role of international trade in agricultural policies and performance. Special attention is given to the situation of Chinese agriculture.  相似文献   

6.
The agriculture, forestry and other land use (AFOLU) sector is responsible for approximately 25% of anthropogenic GHG emissions mainly from deforestation and agricultural emissions from livestock, soil and nutrient management. Mitigation from the sector is thus extremely important in meeting emission reduction targets. The sector offers a variety of cost‐competitive mitigation options with most analyses indicating a decline in emissions largely due to decreasing deforestation rates. Sustainability criteria are needed to guide development and implementation of AFOLU mitigation measures with particular focus on multifunctional systems that allow the delivery of multiple services from land. It is striking that almost all of the positive and negative impacts, opportunities and barriers are context specific, precluding generic statements about which AFOLU mitigation measures have the greatest promise at a global scale. This finding underlines the importance of considering each mitigation strategy on a case‐by‐case basis, systemic effects when implementing mitigation options on the national scale, and suggests that policies need to be flexible enough to allow such assessments. National and international agricultural and forest (climate) policies have the potential to alter the opportunity costs of specific land uses in ways that increase opportunities or barriers for attaining climate change mitigation goals. Policies governing practices in agriculture and in forest conservation and management need to account for both effective mitigation and adaptation and can help to orient practices in agriculture and in forestry towards global sharing of innovative technologies for the efficient use of land resources. Different policy instruments, especially economic incentives and regulatory approaches, are currently being applied however, for its successful implementation it is critical to understand how land‐use decisions are made and how new social, political and economic forces in the future will influence this process.  相似文献   

7.
可持续农业在当今世界至关重要,因为它有潜力满足我们的农业需求,而这是传统农业无法做到的。这种类型的农业采用一种特殊的耕作技术,既能充分利用环境资源,又能保证不造成任何危害。因此,该技术对环境友好,保证了农产品的安全和健康。微生物种群对推动农业生态系统稳定和生产力的基本过程起着重要作用。若干调查旨在增进对土壤微生物群落的多样性、动态和重要性及其在农业生产力中的有益合作。综述了部分土壤微生物及其对可持续农业生产的重要性。  相似文献   

8.
Historically, agricultural production in the Amazon has been painted as the most environmentally impacting activity. In this study, we investigated the relationship between the increase in agricultural efficiency and the slowdown of deforestation rates in the past decade, correlating these data with municipalities’ agricultural specialization. With the data from the 2006 and 2017 Brazilian Agricultural Census we classified municipalities according to its vegetal or animal specialization and estimated a production frontier using the Stochastic Frontier Analysis (SFA), considering a set of production factors and technological variables. Our results demonstrated that most part of municipalities have no specialization or are based in cattle ranching activities, and the overall agricultural efficiency in the Amazon municipalities grew from 69.5% in 2006 to 74.1% in 2017. The new institutional path in the 21st century contributed to slow deforestation in agricultural activities through an increase in productivity (yield/ha) in the last decade, mainly for vegetal production. Cattle ranching also increased output and efficiency, but it remains the most environmental impacting activity. However, several municipalities could not develop their agricultural production value relative to the most productive areas, suggesting that some factors —technological and productive— that could lead to output increase are not being efficiently allocated, which results in concentrating deforestation in inefficient systems and limiting the effectiveness of current policies. Technological diffusion, especially for small farmers, and private support in environmental issues could contribute to slowdown deforestation without loss of agricultural output.  相似文献   

9.
Latest FAO figures indicate that an estimated 925 million people are undernourished in 2010, representing almost 16% of the population in developing countries. Looking to the future, there are also major challenges ahead from the rapidly changing socio-economic environment (increasing world population and urbanisation, and dietary changes) and climate change. Promoting agriculture in developing countries is the key to achieving food security, and it is essential to act in four ways: to increase investment in agriculture, broaden access to food, improve governance of global trade, and increase productivity while conserving natural resources. To enable the fourth action, the suite of technological options for farmers should be as broad as possible, including agricultural biotechnologies. Agricultural biotechnologies represent a broad range of technologies used in food and agriculture for the genetic improvement of plant varieties and animal populations, characterisation and conservation of genetic resources, diagnosis of plant or animal diseases and other purposes. Discussions about agricultural biotechnology have been dominated by the continuing controversy surrounding genetic modification and its resulting products, genetically modified organisms (GMOs). The polarised debate has led to non-GMO biotechnologies being overshadowed, often hindering their development and application. Extensive documentation from the FAO international technical conference on Agricultural Biotechnologies in Developing Countries (ABDC-10), that took place in Guadalajara, Mexico, on 1-4 March 2010, gave a very good overview of the many ways that different agricultural biotechnologies are being used to increase productivity and conserve natural resources in the crop, livestock, fishery, forestry and agro-industry sectors in developing countries. The conference brought together about 300 policy-makers, scientists and representatives of intergovernmental and international non-governmental organisations, including delegations from 42 FAO Member States. At the end of ABDC-10, the Member States reached a number of key conclusions, agreeing, inter alia, that FAO and other relevant international organisations and donors should significantly increase their efforts to support the strengthening of national capacities in the development and appropriate use of pro-poor agricultural biotechnologies.  相似文献   

10.
The practice of spreading of livestock wastes onto land used for the production of food or animal feeds is widely regarded as the least environmentally damaging disposal method, however, the practice is still fraught with pitfalls such as N pollution of air and water and significant microbiological risks. Therefore this paper focuses on some of the latest developments that provide new insights into the microbiological safety of animal manures, the related treatment options and the spreading the products onto land. In conclusion the paper stresses the need to fully address issues concerning environmental contamination and transmission of antimicrobial-resistant bacteria through livestock manure, improve current environmental regulations regarding manure management practice and coordination of research activities and dissemination of technical information.  相似文献   

11.
Summary Bioengineering approaches provide unprecedented opportunities for reducing poverty, food insecurity, child malnutrition, and natural resource degradation. Genetic engineering offers outstanding potential to increase the efficiency of crop improvement. Thus agricultural biotechnology could enhance global food production and availability in a sustainable way. Small farmers in developing countries are faced with many problems and constraints which biotechnology may assist. Yet, there are varying levels of opposition to the use of this technology in most countries and it is especially intense in Europe. While there is certain public apprehension with the use of bioengineering in food improvement, the primary hurdles facing this technology are the stringent and burdensome regulatory requirements for commercialization, opposition from the special interest groups, apprehension by the food industry especially with the whole foods, and trade barriers including rigid policies on traceability and labeling. Bioengineered crops such as soybean, maize, cotton, and canola with a few traits have already made a remarkable impaet on food production and environmental quality. But, in the developing world, bioengineering of crops such as bananas, cassava, yams, sweet potatoes, sorghum, rice, maize, wheat, millet, and legumes, along with livestock, can elearly contribute to global food security. However, the integration of biotechnology into agricultural research in developing countries faces many challenges which must be addressed: financial, technical, political, environmental, activism, intellectual-property, biosafety, and trade-related issues. To ensure that developing countries can harness the benefit of this technology with minimal problems, concerted efforts must be pursued to create an awareness of its potential benefits and to address the concerns related to its use through dialog among the various stakeholders: policy makers, scientists, trade groups, food industry, consumer organizations, farmer groups, media, and non-governmental organizations. Biotechnology holds great promise as a new tool in the scientific toolkit for generating applied agricultural technologies; however, per se it is not a panacea for the worlds problems of hunger and poverty.  相似文献   

12.
种养一体规模化、集约化是华北平原农业发展的必然趋势,而氮素是连接种植养殖的主要养分资源,以河北津龙循环农业园区为例,采用文献资料、实地调查方法分析农场水平氮素流动特征及利用率,并通过情景分析方法提出农场氮素管理措施,为实现农场水平氮养分资源高效利用、提高农场生产系统生产力和改善华北平原循环农业模式提供技术支撑和科学依据.结果表明: 在农场水平下,化肥和有机肥输入氮量674.6 kg·hm-2·a-1,占总输入氮量的88.3%,氮利用率为41.5%,种植系统氮盈余量190.7 kg·hm-2·a-1,施氮量过多是造成种植系统氮利用率低和氮素盈余量高的主要原因.养殖系统中外购饲料提供氮量占饲料总输入氮量的83.2%,粪尿排氮量为776.6 t·a-1,而还田比例仅为36.3%,氮利用率19.7%.农场水平氮总利用率为40.7%.情景分析表明,农田减少化肥施氮量50%(情景1)、增加来自农场内部玉米籽粒产量(情景2)措施,可分别使种植系统氮利用率提高34.6%和15.6%,同时农场水平氮总利用率分别提高18.7%和9.8%;另外,优化养殖系统饲料结构(情景3),可使氮总利用率提高19.1%.因此,减少化肥氮施用量、调整作物种植结构、优化饲料结构等,是提高农场氮生产力和实现环境友好双赢效果的措施和途径.  相似文献   

13.
黄土高原集水农业研究进展   总被引:48,自引:4,他引:44  
肖国举  王静 《生态学报》2003,23(5):1003-1011
回顾了黄土高原集水农业理论与技术体系的研究成果.分析评价了集水农业的研究进展。随着黄土高原集水农业研究方法的改进、研究内容的深入、研究领域的扩充.提出了广义性集水农业研究范畴。在黄土高原集水农业理论研究的基础上.应加强微集雨微灌溉应用技术、现代集雨技术、计算机控制技术与集雨网络等高新技术手段的技术集成.以提高雨水汇集与利用效率。同时.黄土高原集水农业的研究已经从微生境条件下的农业生态系统延伸至区域生态环境保育。利用汇集雨水合理调配生态用水.进行小流域综合治理。农林牧综合发展。生态环境重建的集水型生态农业是黄土高原集水农业的发展趋势。  相似文献   

14.
Sustainable intensification of agriculture is one of the main strategies to provide global food security. However, its implementation raises enormous political, technological, and social challenges. Meeting these challenges will require, among other things, accurate information on the spatial and temporal patterns of agricultural land use and yield. Here, we investigate historical patterns of agricultural land use (1940–2012) and productivity (1990–2012) in Brazil using a new high‐resolution (approximately 1 km2) spatially explicit reconstruction. Although Brazilian agriculture has been historically known for its extensification over natural vegetation (Amazon and Cerrado), data from recent years indicate that extensification has slowed down and was replaced by a strong trend of intensification. Our results provide the first comprehensive historical overview of agricultural land use and productivity in Brazil, providing clear insights to guide future territorial planning, sustainable agriculture, policy, and decision‐making.  相似文献   

15.
We review agricultural impacts on biodiversity and the potential of conservation agriculture in developing productive and environment-friendly cropping systems. We then analyse experiences from two African landscapes of global importance for conservation: the Mid Zambezi Valley in Southern Africa and the periphery of the “W-Arly-Penjari” complex in West Africa. In both areas, expansion of cotton farming, considered as one of the most polluting forms of agriculture in the world, drives major land use change and loss of biodiversity. In both areas, various forms of conservation agriculture have been developed and tested. We highlight the potential benefit of conservation agriculture in controlling negative environmental effects traditionally associated with agriculture and reducing the need for land conversion through increased biophysical resource use efficiency, turning agriculture from a threat to an opportunity for conservation. Finally, we raise a number of issues that constitute challenges for the widespread adoption of these technologies by resource-poor farmers, and formulate recommendations for the development, evaluation and diffusion of conservation agriculture technologies for smallholders in semi-arid Africa.  相似文献   

16.
Nitrogen (N) fertilization in agriculture has been discussed controversially in Germany for almost two centuries. The agronomist Carl Sprengel, who published his theory on the mineral nutrition of plants in 1828, advocated the use of mineral N fertilizers. Chemist Justus von Liebig, on the other hand, vehemently denied around 1850 the need for N fertilization. Although it soon became evident that Sprengel was right and Liebig was wrong, not much synthetic N fertilizer was used in German agriculture until around 1915, when the Haber-Bosch technique enabled the commercial production of NH3. The use of N fertilizers since then has grown, especially since 1950. To increase agricultural productivity, German governments have promoted, directly and indirectly, the use of N in crop and in animal production. Unfortunately, it was overlooked that N surpluses in agriculture increased rapidly; around 1980 they amounted yearly to more than 100 kg ha(-1). The extensive use of N in agriculture is causing environmental damage and is contributing substantially to the external costs of present agriculture. The main N compounds that affect the environment are N2O, NH3, and NO3. These compounds are considered to contribute one third to the external costs of agriculture. Additionally, the high rate of human intake of animal proteins and lipids has adversely affected the health of the country's population. Fundamental corrections in German farm policy appear inevitable.  相似文献   

17.
Latest FAO figures indicate that an estimated 925 million people are undernourished in 2010, representing almost 16% of the population in developing countries. Looking to the future, there are also major challenges ahead from the rapidly changing socio-economic environment (increasing world population and urbanisation, and dietary changes) and climate change.Promoting agriculture in developing countries is the key to achieving food security, and it is essential to act in four ways: to increase investment in agriculture, broaden access to food, improve governance of global trade, and increase productivity while conserving natural resources. To enable the fourth action, the suite of technological options for farmers should be as broad as possible, including agricultural biotechnologies. Agricultural biotechnologies represent a broad range of technologies used in food and agriculture for the genetic improvement of plant varieties and animal populations, characterisation and conservation of genetic resources, diagnosis of plant or animal diseases and other purposes. Discussions about agricultural biotechnology have been dominated by the continuing controversy surrounding genetic modification and its resulting products, genetically modified organisms (GMOs). The polarised debate has led to non-GMO biotechnologies being overshadowed, often hindering their development and application.Extensive documentation from the FAO international technical conference on Agricultural Biotechnologies in Developing Countries (ABDC-10), that took place in Guadalajara, Mexico, on 1–4 March 2010, gave a very good overview of the many ways that different agricultural biotechnologies are being used to increase productivity and conserve natural resources in the crop, livestock, fishery, forestry and agro-industry sectors in developing countries. The conference brought together about 300 policy-makers, scientists and representatives of intergovernmental and international non-governmental organisations, including delegations from 42 FAO Member States. At the end of ABDC-10, the Member States reached a number of key conclusions, agreeing, inter alia, that FAO and other relevant international organisations and donors should significantly increase their efforts to support the strengthening of national capacities in the development and appropriate use of pro-poor agricultural biotechnologies.  相似文献   

18.
Humanity is facing possibly the greatest challenge in its history. Population is expected to reach 9 billion in 2030. At the same time agricultural land is becoming scarcer and poorer in quality. Furthermore, the environmental impact of intensive agriculture and the effects of climate change are threatening food security in many regions of the globe. Further, shortage of fossil fuels will have dramatic effects on the performance of intensive agriculture. There is an urge to develop more ecological agricultural practices both to meet the need to preserve agroecosystems health and to deal with the reduced availability of “cheap” energy from fossil fuels. This paper reviews a number of studies comparing the performances of conventional and organic agriculture in light of energy use, CO 2 emission and other environmental issues. Organic agriculture, along with other low input agriculture practices, results in less energy demand compared to intensive agriculture and could represent a means to improve energy savings and CO2 abatement if adopted on a large scale. At the same time it can provide a number of important environmental and social services, such as preserving and improving soil quality, increasing carbon sink, minimizing water use, preserving biodiversity, halting the use of harmful chemicals, thereby guaranteeing healthy food to consumers. We claim that more work should be done in terms of research and investment to explore the potential of organic farming for reducing environmental impact of agricultural practices. However, in the case of organic agriculture, the implications of a reduced productivity for the socioeconomic system should be considered and suitable agricultural policies worked out.  相似文献   

19.
Agricultural sustainability: concepts, principles and evidence   总被引:1,自引:0,他引:1  
Concerns about sustainability in agricultural systems centre on the need to develop technologies and practices that do not have adverse effects on environmental goods and services, are accessible to and effective for farmers, and lead to improvements in food productivity. Despite great progress in agricultural productivity in the past half-century, with crop and livestock productivity strongly driven by increased use of fertilizers, irrigation water, agricultural machinery, pesticides and land, it would be over-optimistic to assume that these relationships will remain linear in the future. New approaches are needed that will integrate biological and ecological processes into food production, minimize the use of those non-renewable inputs that cause harm to the environment or to the health of farmers and consumers, make productive use of the knowledge and skills of farmers, so substituting human capital for costly external inputs, and make productive use of people's collective capacities to work together to solve common agricultural and natural resource problems, such as for pest, watershed, irrigation, forest and credit management. These principles help to build important capital assets for agricultural systems: natural; social; human; physical; and financial capital. Improving natural capital is a central aim, and dividends can come from making the best use of the genotypes of crops and animals and the ecological conditions under which they are grown or raised. Agricultural sustainability suggests a focus on both genotype improvements through the full range of modern biological approaches and improved understanding of the benefits of ecological and agronomic management, manipulation and redesign. The ecological management of agroecosystems that addresses energy flows, nutrient cycling, population-regulating mechanisms and system resilience can lead to the redesign of agriculture at a landscape scale. Sustainable agriculture outcomes can be positive for food productivity, reduced pesticide use and carbon balances. Significant challenges, however, remain to develop national and international policies to support the wider emergence of more sustainable forms of agricultural production across both industrialized and developing countries.  相似文献   

20.
The manure produced by livestock animals across all of Japan is approximately 90 million tonnes a year, which represents approximately 25% of the overall biomass of Japan's natural resources. In recent decades, the supply of the livestock animal compost has decreased due to various factors—a decrease in fodder, decrease in deserted cultivated land and increase in the importation of fodder—while the domestic animal manure portion of the livestock waste and associated increases have risen dramatically. Most of this manure leads to negative environmental effects by increasing nitrogen (N) loads in rainfall events and causing excess fertilisation, especially in agricultural areas. Animal manure accounts for approximately 23% of all categories of waste in Japan and 89% of all livestock waste in Japan. This 89% of livestock waste is generally utilised as compost or fertiliser. In Japan, the oversupply of fertiliser has already been identified as a problem in the field of agriculture. To address these issues, we assessed the two-dimensional (2D) concentration distribution of N in a water system to specifically analyse the effect of livestock contamination. From the results of this analysis, we observed that industrial factory wastewater creates a narrow localised impact, while the livestock industry creates a medium/broad impact. Therefore, this study provided a simultaneous representation of the total and specific impacts of both human and livestock activities under typical rural catchment conditions. The difference between the environmental impact index value of the current situation and the policy effect was quantitatively assessed. These results will contribute to the construction of a practical decision-making method. Additionally, reduced greenhouse gas emissions, a widely expanded network of protected areas and/or efforts to provide corridors to ease species movement may be necessary to achieve more globally sustainable practices.  相似文献   

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